Patent document 1 (Japanese Patent Application Laid-Open No. 7-250485) describes an inverter. The inverter includes an upper side switching element and a lower side switching element connected in series to each other between two direct current (DC) power supply lines. A first internal control circuit for providing a switch signal is connected to the upper side switching element, and a second internal control circuit for providing a switch signal is connected to the lower side switching element.
The DC power supply is supplied to the second internal control circuit as the operation power supply. A voltage between both ends of a capacitor is supplied to the first internal control circuit as the operation power supply. A diode is connected between one end on a high potential side of the capacitor and one end on a high potential side of the DC power supply. The diode is arranged with an anode directed towards the DC power supply.
According to such configuration, the capacitor is charged with the DC power supply as a power supply by conduction of the lower side switching element.
Techniques related to the present invention are also disclosed in Japanese Patent No. 4158715 and Japanese Patent Application Laid-Open No. 2007-295686.